The present invention relates to a multichannel magnetic head and a method for manufacturing the multichannel magnetic head and a card reader using the same. More specifically, the present invention relates to improvements in a magnetic recording means to record magnetic data onto a magnetic card.
When a magnetic head that reads and records magnetic data from and a magnetic medium, such as a magnetic card, is sufficiently in contact with the magnetic card, recording (writing) is easily performed and reading and recording can be excellently performed. However, the contact between the magnetic head and the card may not always be sufficiently good thus potentially causing unacceptable results.
For example, and with reference to FIG. 32, when magnetic recording portion 102 of magnetic card 101 is formed in three tracks (also called xe2x80x9cchannelsxe2x80x9d), a space exists between magnetic head 103 and magnetic card 101 if the card is warped. As a result, especially when the second channel in the middle is separated from magnetic head 103, recording and reading may not be sufficiently performed. The same phenomenon can be observed with multichannel magnetic card 101 having a plurality of channels wherein magnetic information may not be sufficiently transferred in the vicinity of the center of magnetic recording portion 102 due to spacing.
The above problem would not occur if magetic cards never warp. However, it is difficult to completely prevent a card from warping. JIS (Japanese Industrial Standard) allows a spacing that is less than 2 mm between the magnetic recording portion 102 and magnetic head 103, taking into account the possibility that magnetic card 101 is slightly warped.
Magnetic card 101 tends to have a high coercive force and recently magnetic heads have been designed for high-coercive-force-cards. As a result of such design, recording of magnetic information is not sufficiently performed even when the spacing between the magnetic card and a magnetic head is within the allowance (e,g, 2 mm). While a higher coercive force is provided to the card to improve the coercive force of the recording magnetism and thus the coercive force itself is improved, magnetic recording ability is nonetheless substantially reduced as compared to the sufficient recording achieved by a conventional magnetic card and magnetic head when low coercive force is used. Therefore, even when the spacing is within the allowance, magnetic recording to magnetic card 101, especially to the second channel, may not be sufficiently performed.
When magnetic card 101 is transferred to the magnetic card reader, the magnetic card is pressed against magnetic head 103 by a pat roller during recording and reproduction. However, when the surrounding temperature is low, the magnetic card tends to harden which in turn prevents the card from flattening out by the pressing. The operation of a magnetic card reader generally is guaranteed between temperatures of 0 to 50C. When the temperature falls below this range, the above-mentioned problem becomes prominent.
Therefore, it is an object of the present invention to provide a multichannel magnetic head and a method for manufacturing a multichannel magnetic head in which magnetic information is sufficiently recorded even when a relatively large space exists between the magnetic recording portion and the magnetic head due to warping of the magnetic card.
It is a further object of the present invention intends to provide a magnetic card reader using the above multichannel magnetic head.
Various other objects, advantages and features of the present invention will become readily apparent to those of ordinary skill in the art, and the novel features will be particularly pointed out in the appended claims.
To achieve the object stated objects, and in accordance with the present invention, there is provided a plurality of channels, that form the magnetic recording portion of a magnetic card, that have different density of recording magnetism. By applying this characteristic feature of the present invention to a card reader, recording can be sufficiently performed even when a relatively large spacing exists between a high coercive force card and a coercive magnetic head.